Azo dyestuff



Patented Nov. 6, 1928.

UNITED STATES PATENT OFFICE.

WALTER DUIBIBERG, OF LEVEBKUSEN, NEAR COLOGNE. AND WINFRIID HENTBICH AND LUDWIG 2113:, OF WIESDORF, NEAR COLOGNE, GERMANY, ASSIGNOBS TO GRAS- SELLI DYESTUFF CORPORATION, OF NEW YORK, N. Y., A. CORPORATION OF DELA- WARE.

AZO DYESTUFF.

No Drawing. Application Med December 8, 1925, Serial No. 74,163, and in Germany December 19, 1924.

It is known that dyestuffs form (1 by the combination of, diazotized o-amino enzaldehyde with various coupling components are unstable. Kobylinsky (Dissertation Ros- 5 took, 1901) shows, for instance, that the dye stuff formed from o-aminobenzaldehyde and B-naphthol even in indifl'erent solvents such as other readily changes into the colorless oxyindazol derivative.

If it is attempted to produce dyes from the oxim of theo-aminobenzaldehyde, the results are negative. Bamberger and Weiler, J ourn. f. prakt. Chemie, vol. 58, II, 1898, page 342, show that in this case a rin closure takes place as a result of the diazotization.

It has now been found that thoroughly stable dyes may be obtained by treating the product of the combination of diazotized o-aminobenzaldehyde with various coupling components with hydroxylainine. These dyes are of especial interest in view of their property of easily forming stable metal compounds.

The invention is illustrated by the following examples:

(1) 121 arts of o-aminobenzaldehyde are diazotized 1n the usual way and coupled in an alkaline sodium carbonate solution with 337 parts of the sodium salt of Q-phenylamino-8-naphthol-6-sulfonic acid. When the coupling is complete the resulting azo compound is salted out, thoroughly washed with a solution of sodium chloride, mixed to a paste with water and then stirred for 24 hours with a solution of 139 parts of hydroxylamine hydrochloride and twice the amount of sodium acetate theoreticall required; for example, 164 parts of anhy rous sodium acetate or a corresponding amount of crystalline sodium acetate. The resultin dyestuif is filtered out and washed with a so ution of sodium chloride and dried. In its dry pulverized form it is a dark brown owder soluble in water and in concentrate sulfuric acid, forming brown colored solutions. It has in the form of the free acid most probably the formula It dyes wool a clear brown color. By treating the dyed wool with chromium salts the color is intensified and its fastness properties improved.

(2) 121 parts of o-aminobenzaldehyde are diazotized in the usual way and coupled in an alkaline sodium carbonate solution with 347 parts of 1-ethylamino-8-naphthol-3.6-disulfonic acid. The coupling takes place quickly. The resulting azo compound is filtered ofl, thoroughly washed with a sodium chloride solution and thereafter treated with hydroxylamine as described in Example (1). The resulting dyestuff in its dry pulverized form is a dark colored powder, soluble in water and in concentrated sulfuric acid with a claret color. It has in the form of the free acid most probably the formula:

on H N/ t:% 0H NH-OzHn Ems om It dyes wool a claret color which becomes blue upon the treatment of the dyed wool with copper salts.

(3) 121 parts of o-aminobenzaldehyde are diazotized in the usual way and coupled in an acetic acid solution with 254 parts of methyl- 4-sulfophenylpyrazolon. The resultin azo compound is filtered off, quickly washe with water and stirred for 24 hours in a solution of 139 parts of hydroxylamine hydrochloride (twice the amount theoretically required) and twice the amountof sodium acetate theoretically required; for example, 164 parts of anhydrous sodium acetate or a corresponding amount of crystalline sodium acetate. The resultingdyestufi is filtered oil and dried. It has in the form of the free acid most probably the formula:

CHr-C=N N=N -o It dyes wool a clear yellow color, which .by treating the dyed wool with copper salts changes to a yellowish brown.

The process described may be varied by sim ly neutralizing the acetic acid solution of t e azo compound and immediately treating the resulting mass with the hydroxylamine hydrochloride and sodium acetate. In this way the azo compound which as soon as itis formed be ins to change and is diflicult to handle is sta ilized.

(4) 242 parts of o-aminobenzaldehyde are diazotized in the usual way and coupled in an alkaline solution with 461 parts of 5.5- dihydroxy-7.7disulfo-2.2'-dinapthylamine. The resulting azo com ound is washed by decantation, filtered, was ed again with sodium 1,eeo,774

chloride solution, diluted to a paste with water, stirred for 24 hours at room temperature with a solution of 278 parts of hydroxylamine hydrochloride (twice the quantity theoretically required) and twice the quantity of sodium acetate theoretically required; for example, 328 parts of anhydrous sodium acetate or a corresponding amount of crystalline sodium acetate and finally filtered oil and dried. In its pulverized form it is a dark colored powder soluble in water and in concentrated sulfuric acid. It has in the form of the free acid most probably the formula:

H on on NE H|S 50:11

It dyes cotton a deep claret color and gives by treatment with copper salts clear violet dyeings which are very fast to light and washmg.

137 arts of o-aminobenzoic acid are diazotized 1n the usual way and coupled in an acetic acid solution with 504 parts of 5.5- dihydroxy-2.2'-dinaphthylurea-7'-disulfonic acid. After the couplingis completed the reaction mixture is rendered alkaline with sodium carbonate and there is added to it an icecold solution of diazotized o-aminobenzaldehyde. A second coupling takes placequickly.

.see Berichte, Vol.17, p

It dyes cotton a clear red color which upon treating the dyed cotton with copper salts is changed to a deep brownish-red shade.

Instead of the diazo com und of o-aminobenzoic acid of Example l various other diazo compounds ma be used and the oaminobenzaldehyde o the several examples may be substituted by its substitution products as well as by the compound produced by treating its so-called anhydrid:

457 (1884) with concentrated hydrochloric acid. The anhydride hydrolizes during the reaction so that the same dyestuffs are obtained in this case as when o-aminobenzalldehyde is used directly. i i

In the appended claims azo compound of o-aminobenzaldehyde is understood to in- 4 clude the azo compounds of o-aminobenzaldehyde itself and its substitution We claim: 1. Procesof making azo dyestufl's which products.

\ zen-004m no The resulting azo compound is salted out and filtered oil and treated, as described in the foregoing exam les, with a solution of 139 parts of hy roxylamine hydrochloride (twice the quantity theoretically required) and twice the quantity of sodium acetate theoreticall required; for example, 164 parts of an ydrous sodium acetate or a correspondin amount of crystalline sodium acetate. l heresultin dye-stufl' is filtered oil and dried. It has in the form of the free acid most probably the formula:

comprises treating azo compounds of oaminobenzaldehyde with hydroxylamine.

2. A d estufl's substantially identical with dyestu 5 obtained by treating azobompounds of o-aminobenzaldehyde with bydroxylamine.

in which R is a radical containing two naphthalene nuclei connected by a nitrogen containing linka e of the group including 5. An azo dyestufi having in the form of NH and .CO.NH. the free acid the formula:

In testimony whereof, we alfix our signatures.

WALTER DUISBERG. WINFRID HENTRICH. LUDWIG ZEH.

CERTIFICATE QF CORRECTION.

5 Patent No. 1,6!1, 774. Granted November 6, 1928, to

WALTER DUISBERG ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2. line 34, for "7 prime-disultouic" reed "7.7 prime-disulfonic"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 11th day of December, A. D. I928.

M. J. Moore, (Seal) Acting Commissioner of Patents.

containing linka e of the group including 5. An azo dyestufi having in the form of NH and .CO.NH. the free acid the formula:

In testimony whereof, we alfix our signatures.

WALTER DUISBERG. WINFRID HENTRICH. LUDWIG ZEH.

CERTIFICATE QF CORRECTION.

5 Patent No. 1,6!1, 774. Granted November 6, 1928, to

WALTER DUISBERG ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2. line 34, for "7 prime-disultouic" reed "7.7 prime-disulfonic"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 11th day of December, A. D. I928.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

